Muscle Structure and Function Quiz

What is the basic functional unit of a muscle called?

• Sarcomere

• Myofibril

• Muscle fiber

• Fascicle

Which type of muscle tissue is under voluntary control?

• Cardiac muscle

• Smooth muscle

• Skeletal muscle

• Epithelial muscle

Explain how the sliding filament theory describes muscle contraction.

• Actin and myosin filaments slide past each other, shortening the sarcomere.

• Myosin filaments dissolve, allowing actin to contract.

• Actin filaments break down, causing muscle contraction.

• Myosin filaments elongate, pushing actin filaments apart.

Identify the protein that binds calcium ions to initiate muscle contraction.

• Tropomyosin

• Troponin

• Myosin

• Actin

Describe the role of ATP in muscle contraction.

• ATP provides energy for the detachment of myosin heads from actin.

• ATP binds to actin, causing it to contract.

• ATP is stored in the sarcoplasmic reticulum for future use.

• ATP is converted into ADP, which powers the contraction.

Which of the following is NOT a function of muscles in the human body?

• Producing movement

• Maintaining posture

• Storing calcium

• Generating heat

Compare the structure of cardiac muscle to skeletal muscle.

• Both have striations, but cardiac muscle cells are branched and connected by intercalated discs.

• Cardiac muscle is smooth and lacks striations, unlike skeletal muscle.

• Skeletal muscle cells are branched, while cardiac muscle cells are not.

• Both types of muscle have no striations and are involuntary.

What is the role of the sarcoplasmic reticulum in muscle cells?

• It stores and releases calcium ions.

• It synthesizes proteins for muscle repair.

• It generates electrical impulses for contraction.

• It provides structural support to the muscle cell.

How does the nervous system communicate with muscles to initiate contraction?

• By releasing hormones into the bloodstream.

• Through electrical impulses transmitted via motor neurons.

• By increasing blood flow to the muscles.

• By altering the pH of the muscle tissue.

Which of the following best describes the role of myoglobin in muscle cells?

• It stores oxygen for use during muscle contraction.

• It breaks down glucose for energy.

• It transports calcium ions within the cell.

• It provides structural support to the muscle fiber.